+ def _refresh_area(self, area) -> bool:
+ """Loop through dirty areas and redraw that area."""
+ # pylint: disable=too-many-locals, too-many-branches
+
+ clipped = Area()
+ # Clip the area to the display by overlapping the areas.
+ # If there is no overlap then we're done.
+ if not self._core.clip_area(area, clipped):
+ return True
+
+ rows_per_buffer = clipped.height()
+ pixels_per_word = 32 // self._core.colorspace.depth
+ pixels_per_buffer = clipped.size()
+
+ # We should have lots of memory
+ buffer_size = clipped.size() // pixels_per_word
+
+ subrectangles = 1
+ # for SH1107 and other boundary constrained controllers
+ # write one single row at a time
+ if self._core.sh1107_addressing:
+ subrectangles = rows_per_buffer // 8
+ rows_per_buffer = 8
+ elif clipped.size() > buffer_size * pixels_per_word:
+ rows_per_buffer = buffer_size * pixels_per_word // clipped.width()
+ if rows_per_buffer == 0:
+ rows_per_buffer = 1
+ # If pixels are packed by column then ensure rows_per_buffer is on a byte boundary
+ if (
+ self._core.colorspace.depth < 8
+ and self._core.colorspace.pixels_in_byte_share_row
+ ):
+ pixels_per_byte = 8 // self._core.colorspace.depth
+ if rows_per_buffer % pixels_per_byte != 0:
+ rows_per_buffer -= rows_per_buffer % pixels_per_byte
+ subrectangles = clipped.height() // rows_per_buffer
+ if clipped.height() % rows_per_buffer != 0:
+ subrectangles += 1
+ pixels_per_buffer = rows_per_buffer * clipped.width()
+ buffer_size = pixels_per_buffer // pixels_per_word
+ if pixels_per_buffer % pixels_per_word:
+ buffer_size += 1
+ mask_length = (pixels_per_buffer // 8) + 1 # 1 bit per pixel + 1
+ remaining_rows = clipped.height()
+
+ for subrect_index in range(subrectangles):
+ subrectangle = Area(
+ clipped.x1,
+ clipped.y1 + rows_per_buffer * subrect_index,
+ clipped.x2,
+ clipped.y1 + rows_per_buffer * (subrect_index + 1),
+ )
+ if remaining_rows < rows_per_buffer:
+ subrectangle.y2 = subrectangle.y1 + remaining_rows
+ remaining_rows -= rows_per_buffer
+ self._core.set_region_to_update(subrectangle)
+ if self._core.colorspace.depth >= 8:
+ subrectangle_size_bytes = subrectangle.size() * (
+ self._core.colorspace.depth // 8
+ )
+ else:
+ subrectangle_size_bytes = subrectangle.size() // (
+ 8 // self._core.colorspace.depth
+ )
+
+ buffer = memoryview(bytearray([0] * (buffer_size * 4)))
+ mask = memoryview(bytearray([0] * mask_length))
+ self._core.fill_area(subrectangle, mask, buffer)
+
+ # Can't acquire display bus; skip the rest of the data.
+ if not self._core.bus_free():
+ return False
+
+ self._core.begin_transaction()
+ self._send_pixels(buffer[:subrectangle_size_bytes])
+ self._core.end_transaction()
+ return True